destroying at least 40 buildings. defense attorneys are calling witnesses to the stand in the trial of george zimmerman. yesterday we heard from tracy martin, trayvon martin's father. he denied claims he told police investigators the screaming voice on a 911 tape was not his son's. >> do you recall officer asking you whether you could identify your son's voice? >> not -- not those exact words, but some to that nature, yes. >> okay. do you recall the words, as best that you can recall, he used? >> as best that i recall, that he played the tape. he basically just said, do you recognize the voice? >> and what was your response? >> my response was, that's -- i didn't tell him -- i didn't tell him, no, that wasn't trayvon. i kind of -- i think the chairs had wheels on them and i kind of pushed away from the -- away from the table and just kind of shook my head and said, i can't tell.